Key points:

In a statement on its website, TAK named the woman bomber as Seher Cagla Demir, who had been involved since 2013 in a "radical fight against a policy of massacre and denial against the Kurdish people".

"On the evening of March 13, a suicide attack was carried out ... in Ankara, the heart of the fascist Turkish republic," the statement said.

"We claim this attack targeting centres... where decisions to massacre Kurdish people are made."

The claim came as Germany said it had closed its embassy in Ankara and its general consulate in Istanbul because of indications that an attack could be imminent.

A German school in Istanbul was also shut due to an "unconfirmed warning", the German Foreign Ministry said.

The increased violence in Turkey has also put strain on the NATO member's relationship with the United States, which is supporting a Syrian Kurdish militia, the YPG, in the fight against Islamic State militants in Syria.